This is a cosplay of the newer version of DC Comics' Catwoman. Instead of the Michelle Pfeiffer/Halle Berry mask, this Catwoman wears a traditional hood-style cowl and a pair of goggles (kinda steampunk already). It's the style of Catwoman costume seen most recently in Arkham City and the tv show Gotham.

When you're cosplaying a well-known character, it can be hard to make significant changes to their costume without losing their overall identity. The last thing you want to hear is, "who are you supposed to be?" In this photo, our Steampunk Catwoman has managed to add a few Victorian elements to her costume, while keeping recognizable character details, like the whip and cat ear cowl. She also managed to maintain the sexiness of the character without resorting to the traditional full-body catsuit.

COWL

This style of Catwoman cowl is not easy to find. Most costume stores sell the tight rubber Catwoman masks with fake stitching that cover the eyes and head. Sometimes you can find some options on Etsy or Ebay, but it's pretty hit or miss. Here is one option, although it requires 3-5 weeks process time: DC Comics Cosplay Prop - Catwoman Hat:

This version doesn't actually cover the head, but it still gives the appearance of Catwoman's cowl. It's a headband, so you could always try placing it over/under a black hood to give a similar look. Leg Avenue Femme Fatale Mask:

GOGGLES

There are so many goggle options, but these appear to be the ones Steampunk Catwoman is wearing. Aluminum Welding Goggles:

CORSET

Corsets are a staple of Steampunk fashion, and a great way to keep a character sexy. The brocade fabric of Catwoman's overbust corset adds some texture and depth to the black-on-black outfit. Feminine details like the ruffle ruched trim and ribbon tie front keep it flirty. This is the same corset Catwoman is wearing in the above photo. Satin Sweetheart Overbust Corset Bustier: